bubbling1.gifMwaterAnim.gifmulti-word fill quiz 9Fwf2 on "Patterns of reactivity"
(a doc brown worksheet for QCA KS3 science-chemistry)

Site Meter* Do online OR printout, do, return to check answers. * KS3 Science Index * EMAIL comment?query * Doc Brown's Chemistry updated June 11th 2009 *

   14      7      alkali      calcium      chemical      colourless      dangerous      exothermic      glasses      green      heat      hydrogen      hydroxide      ignites      metal      new      potassium      purple      screen      sodium      test      tube   
1. Some metals like react with cold water to form an and a gas.

2. If the gas is collected in an inverted (upside down!) of water (tricky!) and a lit splint applied it pops! showing the gas to be .

3. If universal indicator is added to the water, during the reaction it changes from (pH ) to (pH ), showing an alkaline solution is formed.

4. This reaction is , it should be done behind a safety and safety should be worn.

5. You can tell a change is taking place because is given out and bubbles are seen as substances are formed.

6. The reaction of potassium with water is so , that the heat given out the hydrogen gas and lilac flame is seen.

7. The general equation for the reaction is:
(a) metal + cold water ==> hydroxide + hydrogen

so complete the following ...
(b) + water ==> potassium hydroxide + hydrogen
(c) calcium + water ==> +